Add fullscreen navbar-tool

Author: z-song

src/Widgets/Navbar/Fullscreen.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace Encore\Admin\Widgets\Navbar;
+
+use Encore\Admin\Admin;
+use Illuminate\Contracts\Support\Renderable;
+
+/**
+ * Class FullScreen
+ *
+ * @see  https://javascript.ruanyifeng.com/htmlapi/fullscreen.html
+ */
+class Fullscreen implements Renderable
+{
+    public function render()
+    {
+        $script = <<<'SCRIPT'
+function launchFullscreen(element) {
+  if(element.requestFullscreen) {
+    element.requestFullscreen();
+  } else if(element.mozRequestFullScreen) {
+    element.mozRequestFullScreen();
+  } else if(element.msRequestFullscreen){
+    element.msRequestFullscreen();
+  } else if(element.webkitRequestFullscreen) {
+    element.webkitRequestFullScreen();
+  }
+}
+
+function exitFullscreen() {
+  if (document.exitFullscreen) {
+    document.exitFullscreen();
+  } else if (document.msExitFullscreen) {
+    document.msExitFullscreen();
+  } else if (document.mozCancelFullScreen) {
+    document.mozCancelFullScreen();
+  } else if (document.webkitExitFullscreen) {
+    document.webkitExitFullscreen();
+  }
+}
+
+$('.nav-fullscreen').click(function () {
+    if (document.fullscreenElement) {
+        exitFullscreen();
+    } else {
+        launchFullscreen(document.body)
+    }
+});
+
+SCRIPT;
+
+        Admin::script($script);
+
+        return <<<'EOT'
+<li>
+    <a href="javascript:void(0);" class="nav-fullscreen">
+      <i class="fa fa-arrows-alt"></i>
+    </a>
+</li>
+EOT;
+    }
+}